There are two theories on doing water changes that I know of. Then there is my theory.

1. Don't change ANY water during cycling because you want to develop the heavy bacteria colonies needed for future bio loads.

2. Do water changes to keep some of the stuff alive on the rocks.

3. Only do a couple small water changes during cycling to keep the spike from going too high, but also make a large screened in box and fill it with grape caulerpa for nutrient exporting as well as a fast growing food source for the tangs and other herbivores.